Equalizing foot attachment



Nov. 24, 1959 A. CROUCH EQ UALIZING' FOOT ATTACHMENT Filed May 28, 1957INVENTOR. Elmer A. C'rauc/r 463Y 45 M aw 197 TURNED S EQUALIZING FOOTATTACHMENT Elmer A. Crouch, Newtown, Conn., assignor to Seeger-Williams. lnc., Bridgeport, Conn., a corporation of The presentinvention relates to an attachment for ladders or the like for enablinga ladder to be stable and safe when supported by its ends on unevensurfaces.

The present application is a continuation in part of my copendingapplications, Serial No. 393,432 and Serial No. 505,123, filed November20, 1953, and May 2, .1955, respectively, both now abandoned.

Devices which are utilized to support persons and/or things above theground generally have a plurality of legs whose ends rest on the groundand if they only have two legs such as a ladder, the other end of thelegs rests on a structure, While with three or more legs the devices areself-supporting. In order to provide a safe and sturdy support, it isessential that the ends of the device rest on a flat horizontal surfaceotherwisethe device will be canted or tilted which causes it to beunstable when used. This is particularly true of ladders where the endsof the legs must be in the same horizontal plane or else the ladderbecomes vertically unstable. Naturally this limits the places where aladder may be safely utilized or, even Worse, the user is apt to providewedges or other temporary leveling structures which, though making theladder straight, actually may make the ladder unsafe.

Itis an object of the present invention to provide an attachment for thelegs of devices such as ladders which enable them to be safely used onuneven surfaces such as sloping ground, stairs, etc.

Another object of the present. invention is to provide an attachment asabove set forth which isquickly and easily adjusted to provide aleveling of the ladder and which may be locked in such a position whenin use.

A further object of the present invention is to provide a ladderattachment of the above mentioned type in which the attachment may bepositively locked in the desired position and yet the positive or safetylocking element is unobvious and difficult to accidently manipulate.

Another object of the present invention is to provide an improvedequalizing foot attachment as set forth above which is simple andeconomical in construction, strong and sturdy, and reliable inoperation.

In attaining the above objects the equalizing foot attachment of thepresent invention comprises a foot which is attached to the end portionof a leg of a ladder and is movable with respect to the ladder therebyconstituting in effect a ladder leg adjustable in length. The foot is,

attached to a rod which is axially movable in a base and the latter isfastened to the end portion of the leg of the ladder to extendtherebeyond. The rod and foot are freely movable in an extendingdirection but are automatically locked to the base upon movement in areverse direction. Releasing means are provided to enable retraction ofthe foot after use which consists only of a movable shaft.

A feature of the present invention resides in a safety lock to preventmovement of the shaft and hence unlocking of the rod and this consistsof a rotatable abut ment threaded onto the shaft to be adjusted toprevent any releasing movement of the shaft. -Upon release of the lock,after use, a spring causes retraction of the foot 2,914,135 PatentedNov. 24, 1959 ice to its rest position. Thus, merely holding the ladderin place, extending the foot, if desired, by stepping on it, is all thatis needed to provide a safe and sturdy support, for

a ladder on uneven ground and to prevent the retractionof the foot,either accidently or through mischief, the safety lock is rotated toprevent release of the foot lock. The equalized foot attachment of thepresent invention accordingly acts as a stepless adjustable extensionfor the end of the ladder leg.

Other features and advantages will hereinafter appear.

In the drawing:

Figure 1 is an elevation of the end portion of a ladder with each legbeing provided with an equalizing foot attachment of the presentinvention.

Fig. 2 is a section of the attachment of the present invention shown atits retracted or rest position.

Fig. 3 is a detail sectional view of the safety lock for the releasingmechanism.

Fig. 4 is a section taken on the line 44 of Fig. 2.

Fig. 5 is a section taken .on the line 55 of Fig. 2.

Fig. 6 is an enlarged section of the foot locking mechanism.

Fig. 7 is a detail view of an element of the attachment.

Referring to the drawing, there is shown in Figure 1, a ladder 10 havingrungs .11 and legs 12. While a ladder is shown and specifically referredto in the description of the equalizing foot attachment of the presentinvention, the attachment is usable with other support devices havinglegs such as portable staging, etc. Attached to the lower end portionsof each leg 12 of the ladder are equalizing foot attachments generallyindicated by the reference numeral 12. Though an attachment is shown foreach leg, it will be apparent that only one attachment is required forthe ladder. The ladder 10 is shown being maintained vertically uprighteven on a sloping surface 14 by one attachment being extended to engagethe lower part of the sloping ground to cause the ends of the ladderlegs to be in the same horizontal plane. Though the ladder is shownspecifically as being used on slopping ground, it will be apparent thatit may also be used on stairs and other uneven surfaces where the twoends of the ladder legs cannot, by resting on the surface without theattachment, be located in the same horizontal plane.

The attachment 13 includes a base 15 having a side portion 16 with threeintegral spaced flanges, an upper 17, an

intermediate 18 and a lower 19, extending perpendicularly from the sideportion 16. The lower two flanges 18 and 19 each have an aperture 20 and21 respectively formed therein which are aligned and constitute abearing surface for a hollow rod 22 which is positioned therein andmovable with respect thereto. The rod 22 has attached to its lower end afoot 23 which is the part of the attachment which engages the ground.The upper flange 17 has a pin 24 which holds one end of a spring 25 andthe spring extends through the rod and its other end is fastened theretoby a diametric pin 26 at the foot end of the rod. The spring is undertension and urges the rod to its retracted or rest position shown inFig. 2 in which the rod engages a resilient bumper 27. Snapped into agroove 22a formed in the upper end portion of the rod 22 is a rubberO-ring 22b which engages the flange 18 to preof the plates have holes32a through which a shaft 33 passes. A clip 34 fastens the plates to theshaft so that movement of the shaft causes pivoting of the plates. Theshaft 33 is biased upwardly by a spring 35 circumscribing its upper endportion which causes an upward canting or tilting of the locking plateswith respect to the axis of the rod with the result that a positive lockbetween the rod and plates is automatically caused and maintained.Accordingly, with the above construction, a force exerted axially on therod to extend it encounters no opposition from the locking plates andthis may easily be done merely by stepping on the foot 23 whileadjusting or holding the ladder in its vertical position. The lockingplates prevent any retraction of the rod and lock the rod in the desiredextended position by the edges of the apertures of the plates engagingthe surface of the rod as shown in Fig. 6.

In order to release the lock between the plates 28 and rod 22 there isprovided a releasing mechanism which upon actuation renders ineffectivethe lock and permits the spring 25 to return the rod and foot to theirretracted or rest position. In the specific embodiment shown, thismechanism comprises a manually operable knob 36 fastened to the upperend of the shaft 33 which upon downward movement of it and the shaftagainst the force of the spring 35 causes the locking plates to be movedto a substantially diametric or perpendicular position with respect tothe rod (as indicated in dotted lines, Fig. 6), thus the lock isreleased. The shaft 33 is slidably mounted in a tube 37 which isconnected to the flange 18 by a hollow bolt 38 threading into the tube.The upper end of the tube 37 is provided witha hollow enlarged head 39which rests on the upper flange 17 and in which the spring 35 iscontained. The upper end of the shaft 33 has .a threaded portion 40 onwhich is threaded a flanged nut 41. The nut is freely movable into theenlarged head 39 of the tube and by threading the nut clockwise, the nutadvances on the shaft 33 and into the tube until its flange engages thehead 39 of the tube. In this position, shown in Fig. 3, the shaft 33cannot be moved downward in the tube. The flange of the nut 41 and theend of the tube constitute the safety lock for the releasing mechanism.It will be appreciated that the safety lock is easily rendered effectivesimply by turning of the nut 41 which may 'be knurled to facilitatemanual manipulation. It will further be appreciated that theconstruction of the safety locking mechanism enables quick locking orunlocking and yet 'once locked it provides a positive prevention ofoperation of the releasing mechanism. In addition, the safety lock isnot susceptible to accidental operation and moreover its operation isnot obvious, for example to a child, who may out of curiosity attempt torelease the look.

In order to provide for substantially limitless usage of the attachment,the foot 23 is mounted for universal movement at the end of the rod 22.To this end, the foot, as shown comprises a fiat plate 42 having acorrugated resilient pad 43 and a pair of upstanding ribs 44. The ribshave an aperture 45 through which a pin 46 .passes to fasten the platefor pivotal movement about the pin 46 to a plug 47. A cotter'pin 48 maybe utilized to maintain the pin in place. The plug has a circularreduced end 49 which is received within the end portion of the rod 22and is formed with an annular groove 50 therein. Fitted within thegroove is the central portion of a pin 51 which is secured chordally inthe rod end portion. Thus, the plug is secured to the rod and yet theplug may be rotated with respect thereto. Accordingly, the footmay berotated and pivoted and hencehave a substantially universal movement inorder to accommodate itself to variations in the slope of the surfaces.

The pm 46 is shown in detail in Fig. 7 and is composed of an end portion46a offset from an intermediate portion 4612 located between the offsetportion and an.aperture 460 for the cotter pin and the other end portion46d. In use, the end portions 46a and 46d extend beyond the r1bs 44, andthus provide a surface which may be stepped 4 on to cause extension ofthe rod 22. Thus the users hands are not required to extend theattachment to the position necessary to maintain the ladder verticallystable.

It is presently preferred to releasably fasten the attachment to theladder leg. To this end, the side portion 16 of the base is formed withtwo keyhole slots 52 while fastened to the ladder are two cooperatingheaded lugs 53. Thus the attachment may be securedto the ladder bypassing the heads of the lugs through the larger portion of the keyholeslots 52 and moving the attachment upward with respect to the ladder sothat shanks of the lugs are in the small portion of the slots while thehead is on the outside side of the base, as shown in Fig. 1.

It will thus be appreciated that there has been disclosed an equalizingfoot attachment which provides a reliable and sturdy support enablingthe safe use of a ladder on uneven surfaces. The attachment has a footwhich is adjustable in length and in effect constitutes an adjustableextension of the ladder leg with the extension being substantiallysteplessly adjusted and automatically locked in any desired position. Asimple manual push on a shaft serves to release the lock and a springcauses the foot to snap back to its retracted or rest position.Moreover, according to the present invention, there is a simple yetextremely effective safety lock for the releasing mechanism which isincapable of being accidently operated and in addition is not apt to beoperated mischievously.

Variations and modifications may be made within the scope of the claimsand portions of the improvements may be used without others.

I claim:

An adjustable equalizing supporting attachment for a ladder having a legcomprising an elongate base having a plurality of spaced flanges, saidbase being formed with slots adapted to provide a removable attachmentto with respect to the rod for creating a frictional lock therebetweenand movement of the shaft in a direction againstthe urging of the springfor releasing the lock; a nut threaded on the shaft for movementtherewith; an abutment mounted on a third flange and engaged by the nutfor limiting movement of the shaft, said nut normally permittingmovement of the shaft but being threadable to a position to preventmovement of the shaft and hence unlocking of the frictional look; aspring connected to the rod and normally urging the rod to a retractedposition, whereby said rod upon being unlocked automatically retracts; aplug mounted in the lower end of the rod and having an annular groove;.apin extending chordally of the rod and passing through the groove toretain the plug in the rod yet permit rotation thereof; and a foothaving a flat ground-engaging portion and a pivotal connection to theplug, whereby the foot is rotatable and pivotable with respect to thebase.

, vReferencesCited in the file of this patent UNITED STATES PATENTS7,561 I-Iull Mar. 20, 1877 938,114 Boettcher Oct. 26, 1909 1,177,069Souccie Mar. 28, 1916 2,147,052 Noone Feb. 14, 1939 2,313,469 .ForsmanMar. 9, 1943 .2,495,674 Lewis ,Jan. 24,1950 2,555,036 Husted May. 29,1951 2,603,515 Thomas July 15,1952 2,815,130 Franks Dec. 3, 1957

